<ul>
  <ng-container *ngFor="let node of nodeTree">
    <li *ngIf="node.id" [class]="node.id">
        <a>{{node.text}}</a>
    </li>
    <li *ngIf="node.child">
      <ul>
        <ng-container *ngFor="let node1 of node.child">
          <li *ngIf="node1.id" [class]="node1.id">
              <a>{{node1.text}}</a>
          </li>
          <li *ngIf="node1.child">
            <ul>
              <ng-container *ngFor="let node2 of node1.child">
                <li *ngIf="node2.id" [class]="node2.id">
                  <a>{{node2.text}}</a>
                </li>
                <li *ngIf="node2.child">
                  <ul>
                    <ng-container *ngFor="let node3 of node2.child">
                      <li *ngIf="node3.id" [class]="node3.id">
                          <a>{{node3.text}}</a>
                      </li>
                    </ng-container>
                  </ul>
                </li>
              </ng-container>
            </ul>
          </li>
        </ng-container>
      </ul>
    </li>
  </ng-container>
</ul>